Not good, if you can please return the computer then get your money back. Buying second (or third or later) hand Macs isn't for the unexperienced! The Mac should have been set up per the directions by the seller in What to do before you sell, give away, or trade in your Mac, if it was not then you wasted your money as the computer is associated with the previous owner. In addition, there is a very good chance you inherited someone else's hardware problems.
Moving forward NEVER EVER buy a used Mac from:
Ebay
Nextdoor
Craigslist
Marketplace
Local PC shop
an acquaintance or friend.
The reason being is almost all have NOT be set per the directions above!!!! If you cannot afford a new Mac then buy either an Apple refurbished Mac directly from Apple. You can find these on Apple.com, scroll to the bottom of the page and look in the Refurbished Store. There is ZERO downside to these machines as they are identical to new, come with the same warranty as new, are eligible for AppleCare and can save hundreds of $$$$. If that is still too much money for you then buy from a reputable reseller such as Macsales.com.
We see posts like yours on these forums almost daily and almost always the buyer has wasted their money.